JP2016008252A - Moisture-curable polyurethane hot-melt resin composition, adhesive and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture-curable polyurethane hot-melt resin composition having excellent adhesiveness to various substrates including a polyamide, falling impact resistance and reworkability of a substrate.SOLUTION: There is provided a moisture-curable polyurethane hot-melt resin composition which comprises an urethane prepolymer having an isocyanate group obtained by reacting a polyol (A) containing 0.1 to 5 mass% of a polysiloxane (A-1) having two or more hydroxyl groups and a polyisocyanate (B). Further, there is provided an adhesive containing the moisture-curable polyurethane hot-melt resin composition. In addition, there is provided a laminate having an adhesive layer (ii) composed of the adhesive on a substrate (i) composed of a polyamide.

Description

  The present invention relates to a moisture curable polyurethane hot melt resin composition, an adhesive using the same, and a laminate.

  Moisture-curing polyurethane urethane hot melt adhesives are solvent-free, so various researches have been made to date, focusing on fiber bonding and building material lamination, and are widely used in the industry as environmentally friendly adhesives. .

  In recent years, in response to increasing needs for lighter and thinner optical components, studies have been made on the use of hot melt adhesives instead of acrylic pressure-sensitive adhesives that have been the mainstream in pasting optical components ( For example, see Patent Document 1.)

  However, as adherends (base materials) used for optical members, difficult-to-adhere base materials such as polyamide may be used, and moisture-curable polyurethane hot melt adhesives are directly applied to these base materials. However, there was a problem that satisfactory adhesiveness could not be obtained. Furthermore, the adherend (base material) used for the optical member is often expensive, and if there is a failure during bonding of the optical member, some method should be used to recover the base material. There is a need for a system that can be used to peel an adhesive without any adhesive residue. Thus, although a system that is excellent in adhesiveness and can reduce adhesiveness when desired is craved, it has not been solved yet.

Special table 2011-521040 gazette

  The problem to be solved by the present invention is to provide a moisture-curable polyurethane hot melt resin composition that is excellent in adhesion to various substrates such as polyamide, drop impact resistance and reworkability of the substrate.

  The present invention provides an isocyanate group obtained by reacting a polyisocyanate (B) with a polyol (A) containing a polysiloxane (A-1) having two or more hydroxyl groups in a range of 0.1 to 5% by mass. The present invention provides a moisture curable polyurethane hot melt resin composition characterized by containing a urethane prepolymer.

  The present invention also provides an adhesive comprising the moisture-curable polyurethane hot melt resin composition.

  Moreover, this invention provides the laminated body characterized by having the adhesive bond layer (ii) which consists of said adhesive agent on the base material (i) which consists of polyamide.

The adhesive containing the moisture curable polyurethane hot melt resin composition of the present invention has adhesiveness to various substrates including polyamide film, drop impact resistance, fast curing property, flexibility, waterproof property, ejection property and Excellent shape retention and moderate open time (possible bonding time). Moreover, although the adhesive is excellent in adhesiveness to various substrates, it can be easily peeled off by heating or the like, and therefore has excellent reworkability of the substrate due to peeling of the adhesive.
Therefore, the adhesive obtained by using the moisture-curable polyurethane hot melt resin composition of the present invention can be suitably used not only for fiber bonding and building material lamination, but also for bonding optical members.

  The moisture curable polyurethane hot melt resin composition of the present invention comprises a polyol (A) and a polyisocyanate (B) containing a polysiloxane (A-1) having two or more hydroxyl groups in a range of 0.1 to 5% by mass. It contains a urethane prepolymer having an isocyanate group obtained by reacting as an essential component.

  The polysiloxane (A-1) having two or more hydroxyl groups is a polyol (A) in order to obtain excellent adhesion to a polyamide film which is a difficult-to-adhere substrate, drop impact resistance, dischargeability and reworkability of the substrate. ) In the range of 0.1 to 5% by mass, preferably 0.3 to 3% by mass.

  Examples of the polysiloxane (A-1) having two or more hydroxyl groups include a polysiloxane represented by the following general formula (1), a polysiloxane represented by the following general formula (2), and the following general formula (3). Polysiloxane shown, polysiloxane shown by the following general formula (4), and the like can be used. These polysiloxanes may be used alone or in combination of two or more.

（式（１）中、Ｒ^１及びＲ^３はそれぞれ独立して炭素原子数１〜５のアルキル基を示し、Ｒ^２は炭素原子数１〜５のアルキレン基を示し、ｎは１〜２００の繰り返し単位の平均値を示す。）

(In Formula (1), R ¹ and R ³ each independently represent an alkyl group having 1 to 5 carbon atoms, R ² represents an alkylene group having 1 to 5 carbon atoms, and n represents 1 to 200. Indicates the average value of repeating units.)

（式（２）中、Ｒ^１及びＲ^２はそれぞれ独立して炭素原子数１〜５のアルキレン基を示し、ｎは１〜２００の繰り返し単位の平均値を示す。）

(In Formula (2), R ¹ and R ² each independently represent an alkylene group having 1 to 5 carbon atoms, and n represents an average value of 1 to 200 repeating units.)

（式（３）中、ｎは１〜２００の繰り返し単位の平均値を示す。）

(In formula (3), n represents an average value of 1 to 200 repeating units.)

（式（４）中、Ｒ^１はそれぞれ独立して炭素原子数１〜１０のアルキレン基を示し、Ａｒ^１はそれぞれ独立して炭素原子数２〜３０のアリーレン基を示し、ｎは１〜２００の繰り返し単位の平均値を示す。）

(In Formula (4), R ¹ independently represents an alkylene group having 1 to 10 carbon atoms, Ar ¹ independently represents an arylene group having 2 to 30 carbon atoms, and n represents 1 to 200. The average value of the repeating unit is shown.)

As polysiloxane (A-1) having two or more hydroxyl groups, it is possible to further improve the adhesiveness to the polyamide film (initial adhesive strength and final adhesive strength), drop impact resistance, dischargeability, and reworkability of the substrate. In view of this, it is preferable to use the polysiloxane represented by the general formula (1). Among the polysiloxanes represented by the general formula (1), R ¹ is an ethyl group, R ² is a propylene group, and R ¹ is It is more preferable to use a polysiloxane which represents a butyl group and n is in the range of 5 to 200.

  As the more preferable polysiloxane, for example, “Silaplane FMDA11”, “Silaplane FMDA21”, “Silaplane FMDA26” manufactured by JNC Corporation can be obtained as commercial products.

  As the number average molecular weight of the polysiloxane (A-1) having two or more hydroxyl groups, the adhesiveness to the polyamide film (initial adhesive strength and final adhesive strength), drop impact resistance, dischargeability, and substrate reworkability From the viewpoint, it is preferably in the range of 500 to 100,000, more preferably in the range of 600 to 50,000, and still more preferably in the range of 700 to 30,000. The number average molecular weight of the polysiloxane (A-1) having two or more hydroxyl groups is a value measured under the following conditions by gel permeation chromatography (GPC) method.

Measuring device: High-speed GPC device (“HLC-8220GPC” manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series.
"TSKgel G5000" (7.8 mm ID x 30 cm) x 1 "TSKgel G4000" (7.8 mm ID x 30 cm) x 1 "TSKgel G3000" (7.8 mm ID x 30 cm) x 1 “TSKgel G2000” (7.8 mm ID × 30 cm) × 1 detector: RI (differential refractometer)
Column temperature: 40 ° C
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 mL / min Injection amount: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4 mass%)
Standard sample: A calibration curve was prepared using the following standard polystyrene.

(Standard polystyrene)
"TSKgel standard polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-550" manufactured by Tosoh Corporation

  Examples of the polyol (A) that can be used in addition to the polysiloxane (A-1) include polyether polyol (A-2), crystalline polyester polyol (A-3), polycarbonate polyol (A-4), and amorphous. The polyester polyol (A-5), polyacryl polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, dimer diol and the like can be used. Among these, the polyether polyol (A-2), the crystalline polyester polyol (A-3) and the point that the adhesiveness to the polyamide film, the drop impact resistance, the discharge property and the reworkability of the substrate can be further improved. It is preferable to contain a polycarbonate polyol (A-4), and it is more preferable to further contain an amorphous polyester polyol (A-5) from the viewpoint that adhesion to a polyamide film can be further improved.

  Examples of the polyether polyol (A-2) include polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene glycol, and ethylene oxide-modified polypropylene glycol. These polyether polyols may be used alone or in combination of two or more.

  The number average molecular weight of the polyether polyol (A-2) is in the range of 500 to 5,000 because the adhesiveness (initial adhesive strength and final adhesive strength) can be further improved and the open time is more easily adjusted. It is preferable that it is, and it is more preferable that it is the range of 700-4,500. In addition, the number average molecular weight of the said polyether polyol (A-2) shows the value obtained by measuring similarly to the number average molecular weight of the polysiloxane (A-1) which has two or more of the said hydroxyl groups.

  As content when using the said polyether polyol (A-2), adhesiveness (initial adhesive strength and final adhesive strength) can be improved further, and it is easy to adjust open time, in polyol (A) It is preferable that it is the range of 1-25 mass%, and the range of 5-20 mass% is more preferable.

  The glass transition temperature (Tmg) of the polyether polyol (A-2) is preferably in the range of −70 to 0 ° C. from the viewpoint of further improving the drop impact resistance, and is −50 to −10 ° C. The range of is more preferable. In addition, the glass transition temperature of the said polyether polyol (A-2) shows the value measured by DSC based on JISK7121-1987, and specifically, said (A-2) in the differential scanning calorimeter apparatus. ) And heated up to (Tmg + 50 ° C.) at a heating rate of 10 ° C./min, held for 3 minutes, then rapidly cooled, and shows the midpoint glass transition temperature (Tmg) read from the obtained differential heat curve .

  As the crystalline polyester polyol (A-3), for example, a reaction product of a compound having a hydroxyl group and a polybasic acid can be used. In the present invention, the crystallinity indicates that the peak of crystallization heat or heat of fusion can be confirmed in DSC (Differential Scanning Calorimetry) measurement based on JISK7121-1987. Indicates an item that cannot be confirmed.

  Examples of the compound having a hydroxyl group include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, trimethylolpropane, trimethylolethane, and glycerin. Can do. These compounds may be used alone or in combination of two or more. Among these, it is preferable to use butanediol, hexanediol, octanediol, and decanediol from the viewpoint of improving crystallinity and further improving waterproofness and adhesiveness.

  Examples of the polybasic acid include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, 1,12-dodecanedicarboxylic acid, and the like. These polybasic acids may be used alone or in combination of two or more.

  The number average molecular weight of the crystalline polyester polyol (A-3) is preferably in the range of 500 to 6,000, more preferably in the range of 1,000 to 5,000, from the viewpoint of adhesiveness. preferable. In addition, the number average molecular weight of the said crystalline polyester polyol (A-3) shows the value measured similarly to the number average molecular weight of the polysiloxane (A-1) which has two or more of the said hydroxyl groups.

  The glass transition temperature (Tmg) of the crystalline polyester polyol (A-3) is preferably in the range of 40 to 130 ° C. from the viewpoint of further improving the adhesiveness (particularly the initial adhesive strength). . In addition, the glass transition temperature of the said crystalline polyester polyol (A-3) shows the value measured similarly to the glass transition temperature of the said polyether polyol (A-2).

  The content when the crystalline polyester polyol (A-3) is used is preferably in the range of 1 to 50% by mass in the polyol (A) from the viewpoint of flexibility, adhesiveness and open time. A range of ˜40 mass% is more preferred.

  Further, as the crystalline polyester polyol (A-3), polycaprolactone polyol can be used. As said polycaprolactone polyol, what reacted the compound which has the above-mentioned hydroxyl group, and (epsilon) -caprolactone can be used, for example.

  When polycaprolactone polyol is used as (A-3), the number average molecular weight is preferably in the range of 20,000 to 200,000. The number average molecular weight of the polycaprolactone polyol is a value measured in the same manner as the number average molecular weight of the polysiloxane (A-1) having two or more hydroxyl groups.

  As said polycarbonate polyol (A-4), what is obtained by making carbonate ester and / or phosgene react with the compound which has the above-mentioned hydroxyl group can be used, for example.

  As the carbonate ester, for example, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like can be used. These compounds may be used alone or in combination of two or more.

  The number average molecular weight of the polycarbonate polyol (A-4) is preferably in the range of 500 to 5,000, more preferably in the range of 1,000 to 4,000, from the viewpoint that the adhesion to polyamide can be further improved. More preferably. In addition, the number average molecular weight of the said polycarbonate polyol (A-4) shows the value obtained by measuring similarly to the number average molecular weight of the polysiloxane (A-1) which has two or more of the said hydroxyl groups.

  The glass transition temperature (Tmg) of the polycarbonate polyol (A-4) is preferably in the range of −30 to 20 ° C. from the viewpoint of further improving the drop impact resistance and the adhesion to polyamide. In addition, the glass transition temperature of the said polycarbonate polyol (A-4) shows the value measured similarly to the said polyether polyol (A-2) and glass transition temperature.

  As content in the case of using the said polycarbonate polyol (A-4), it is preferable that it is the range of 20-70 mass% in a polyol (A) from an adhesive point, and the range of 25-70 mass% is more. preferable.

  As the amorphous polyester polyol (A-5), for example, a reaction product of a compound having a hydroxyl group and a polybasic acid can be used.

  Examples of the compound having a hydroxyl group include ethylene glycol, propylene glycol, 1,4-butanediol, pentanediol, 2,4-diethyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, Hexanediol, neopentyl glycol, hexamethylene glycol, glycerin, trimethylolpropane, bisphenol A, bisphenol F, and alkylene oxide adducts thereof can be used. These compounds may be used alone or in combination of two or more. Among these, it is preferable to use an alkylene oxide adduct of bisphenol A from the viewpoint that adhesiveness (particularly, initial adhesive strength) and dischargeability can be further improved. The number of moles of the alkylene oxide added is preferably in the range of 2 to 10 moles, more preferably in the range of 4 to 8 moles.

  Examples of the polybasic acid include adipic acid, glutaric acid, pimelic acid, suberic acid, dimer acid, sebacic acid, undecanedicarboxylic acid, hexahydroterephthalic acid, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid and the like. Can be used. These polybasic acids may be used alone or in combination of two or more. Among these, it is preferable to use sebacic acid and isophthalic acid from the viewpoint that adhesiveness (particularly, initial adhesive strength) and dischargeability can be further improved.

  The number average molecular weight of the amorphous polyester polyol (A-5) is preferably in the range of 500 to 5,000 from the viewpoint of further improving adhesiveness (particularly, initial adhesive strength) and dischargeability. The range of 1,000 to 4,000 is more preferable, and the range of 1,000 to 3,000 is more preferable. In addition, the number average molecular weight of the said amorphous polyester polyol (A-5) shows the value measured similarly to the number average molecular weight of the polysiloxane (A-1) which has two or more of the said hydroxyl groups.

  The glass transition temperature (Tmg) of the amorphous polyester polyol (A-5) is in the range of −50 to −10 ° C. from the viewpoint of further improving the adhesiveness (particularly the initial adhesive strength) and the dischargeability. Preferably there is. In addition, the glass transition temperature of the said amorphous polyester polyol (A-5) shows the value measured similarly to the glass transition temperature of the said polyether polyol (A-2).

  The content when the amorphous polyester polyol (A-5) is used is in the range of 1 to 30% by mass in the polyol (A) from the viewpoint of adhesiveness (particularly, initial adhesive strength) and dischargeability. The range of 5 to 25% by mass is more preferable.

  Examples of the polyisocyanate (B) include aromatic polyisocyanates such as xylylene diisocyanate, polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate; hexamethylene diisocyanate , Cycloaliphatic diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, or other aliphatic or alicyclic polyisocyanates. These polyisocyanates may be used alone or in combination of two or more. Among these, it is preferable to use xylylene diisocyanate from the viewpoint that the adhesion to the polyamide film, the drop impact resistance, and the discharge property can be further improved.

  When obtaining the said urethane prepolymer, you may use together other polyisocyanate with the said xylylene diisocyanate (B) as needed.

  Examples of the other polyisocyanates include polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate isocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, cyclohexane Aliphatic or alicyclic polyisocyanates such as diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and hydrogenated xylylene diisocyanate can be used. These polyisocyanates may be used alone or in combination of two or more. Among these, diphenylmethane diisocyanate is preferable from the viewpoint of reactivity and adhesiveness.

  The urethane prepolymer is obtained by reacting the polyol (A) and the polyisocyanate (B), and reacts with moisture present in the air or in the base material to which the urethane prepolymer is applied. It has an isocyanate group that forms a crosslinked structure. Adhesiveness is manifested by moisture curing of the isocyanate group.

  As a method for producing the urethane prepolymer, for example, a mixture of the polyol (A) is dropped into a reaction vessel containing the polyisocyanate (B) and then heated, and the isocyanate group of the polyisocyanate (B) is changed. The method of manufacturing by making it react on the conditions which become excess with respect to the hydroxyl group which the said polyol (A) has is mentioned.

  When producing the urethane prepolymer, the equivalent ratio ([isocyanate group / hydroxyl group]) of the isocyanate group of the polyisocyanate (B) and the hydroxyl group of the polyol (A) is in the range of 1.1 to 5. It is preferable from the point of the adhesiveness with respect to polyamide, and the drop impact resistance, and the range of 1.5-3 is more preferable.

  The isocyanate group content (hereinafter abbreviated as “NCO%”) of the urethane prepolymer obtained by the above method is in the range of 1.5 to 8% from the viewpoint of further improving the adhesion to polyamide. The range of 1.7 to 5 is more preferable, and the range of 1.8 to 3 is still more preferable. In addition, NCO% of the said urethane prepolymer shows the value measured by the potentiometric titration method based on JISK1603-1: 2007.

  As the viscosity of the urethane prepolymer, the melt viscosity at 125 ° C. is preferably in the range of 1,000 to 50,000 mPa · s, more preferably in the range of 2,000 to 10,000 mPa · s. The range of 4,200 to 7,000 mPa · s is more preferable. The melt viscosity at 125 ° C. of the urethane prepolymer indicates a value measured with a cone plate viscometer (manufactured by ICI).

  The moisture-curable polyurethane hot melt resin composition of the present invention contains the urethane prepolymer as an essential component, but may contain other additives as necessary.

  Examples of the other additives include a curing catalyst, a light stabilizer, an antioxidant, a tackifier, a plasticizer, a stabilizer, a filler, a dye, a pigment, and a silane coupling agent. These additives may be used alone or in combination of two or more. Among these, it is preferable to use a curing catalyst from the viewpoint that the rapid curability can be further improved.

  Examples of the curing catalyst include compounds having a nitrogen atom such as triethylamine, triethylenediamine, N-methylmorpholine; metal salts such as potassium acetate, zinc stearate, tin octylate; dibutyltin dilaurate, stannous octoate, dibutyl Organometallic compounds such as tin diacetate, dibutyltin marker butide, dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin markerbutide and dioctyltin thiocarboxylate; compounds represented by the following general formula (1) can be used. These curing catalysts may be used alone or in combination of two or more. Among these, it is preferable to use a compound represented by the following general formula (5) from the viewpoint that the fast curability can be further improved without impairing the adhesiveness and the drop impact resistance.

（式中、Ｒ^１はそれぞれ独立に水素原子又はアルキル基を示し、ｎ及びｍはそれぞれ独立して１〜６の整数を示す。）

(In the formula, each R ¹ independently represents a hydrogen atom or an alkyl group, and n and m each independently represents an integer of 1 to 6.)

  Among the compounds represented by the general formula (5), the curing catalyst includes 2,2′-dimorpholinodiethyl ether and di (2,6-dimethylmorpholinoethyl) from the viewpoint that the rapid curability can be further improved. It is preferable to use ether.

  As the usage-amount of the said curing catalyst, it is preferable that it is the range of 0.001-5 mass parts with respect to 100 mass parts of said urethane prepolymers from the point of quick-curing property, and 0.05-2 mass parts. A range is more preferred.

  The adhesive obtained by using the moisture-curable polyurethane hot melt resin composition of the present invention has adhesiveness to various base materials including polyamide, drop impact resistance, waterproofness, flexibility, fast curability, It is excellent in coating workability (dischargeability), shape retention after coating, and open time, and can be suitably used not only for fiber bonding and building material lamination but also for bonding optical members.

  As an aspect used for bonding of the said optical member, sealing agents, such as a mobile telephone, a personal computer, a game machine, television, a car navigation system, a camera speaker, are mentioned, for example.

  In the case of performing the bonding, for example, the moisture-curable polyurethane hot melt resin composition is heated and melted in the range of 50 to 130 ° C., the composition is applied onto a substrate, and then the composition is heated. A laminate can be obtained by pasting the other substrate on top.

  Examples of the substrate include glass, polyamide resin, acrylic resin, urethane resin, silicon resin, epoxy resin, fluorine resin, polystyrene resin, polyester resin, polysulfone resin, polyarylate resin, polyvinyl chloride resin, polyvinylidene chloride, Norbornene resin, polyolefin resin, polyimide resin, alicyclic polyimide resin, cellulose resin, PC (polycarbonate), PBT (polybutylene terephthalate), modified PPE (polyphenylene ether), PEN (polyethylene naphthalate), PET (polyethylene terephthalate) , Lactic acid polymer, ABS resin, AS resin and the like can be used. Further, the substrate may be subjected to corona treatment, plasma treatment, primer treatment or the like, if necessary.

  Examples of the method for applying the moisture-curable polyurethane hot melt resin composition to the substrate include a method using a roll coater, spray coater, T-tie coater, knife coater, comma coater, etc .; dispenser, inkjet printing, screen Examples of the method include coating by a method such as printing and offset printing. In particular, the latter application method is preferable because the moisture-curable polyurethane hot melt resin composition can be precisely applied in a small amount on the base material to be applied, so that a loss such as punching does not occur. . Further, according to this coating method, the moisture curable polyurethane hot melt resin composition is continuously formed on the base material in various shapes such as dotted, linear, triangular, square, round, and curved. Or it can form intermittently.

  The thickness of the adhesive layer using the moisture-curable polyurethane hot-melt resin composition can be set according to the intended use, and is preferably in the range of 10 μm to 5 mm, for example.

  As the aging conditions after the bonding, for example, the aging can be performed for 0.5 to 5 days under conditions of a temperature of 20 to 80 ° C. and a humidity of 50 to 90%.

  By the above method, a laminate having the substrate (i) layer firmly bonded and the adhesive layer (ii) made of the moisture-curable hot melt urethane is obtained. As a method for peeling the moisture-curable hot melt urethane adhesive layer from the laminate and recovering the substrate, for example, a method of heating the laminate in the range of 40 to 150 ° C. is preferably used.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Example 1]
In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet and reflux condenser, polytetramethine glycol (number average molecular weight; 2,000, Tmg; −50 ° C., hereinafter abbreviated as “PTMG2000”) .) 10 parts by mass, crystalline PEs-1 (reacted 1,6-hexanediol and sebacic acid, Tmg; 65 ° C., number average molecular weight; 3,500), 15 parts by mass, polycarbonate polyol (Asahi Kasei Chemicals) "Duranol T4672" manufactured by Co., Ltd., number average molecular weight; 2,000, Tmg; 10 ° C, hereinafter abbreviated as "T4672") 60 parts by mass, "Silaplane FMDA11" manufactured by JNC Co., Ltd. (Formula (1)) R ¹ is an ethyl group, ^{R 2} is a propylene group, ^{R 3} is butyl group, indicates the n = 9.7, the number-average molecular weight; 1,000, or less, Abbreviated as FMDA11 ".) Were charged 1 part by mass, water content was dehydrated until 0.05 wt% or less at 100 ° C. under reduced pressure.
Next, after cooling to an internal temperature of 70 ° C., 13.3 parts by mass of xylylene diisocyanate (hereinafter abbreviated as “XDI”) and 0.03 parts by mass of tin octylate are added, and the temperature is raised to 100 ° C. React for about 3 hours until the NCO group content becomes constant to obtain a urethane prepolymer having NCO%; 2.5%, viscosity at 125 ° C .; 6,250 mPa · s isocyanate group, and moisture-curing polyurethane A hot melt resin composition was obtained.

[Examples 2-9, Comparative Examples 1-2]
A moisture curable polyurethane hot melt resin composition was obtained in the same manner as in Example 1 except that the type and / or amount of polyol and the type and / or amount of polyisocyanate were changed as shown in Tables 1 and 2. It was.

[Adhesion evaluation method]
The moisture curable polyurethane hot melt resin compositions obtained in Examples and Comparative Examples were melted at 120 ° C. and applied on a 200 μm thick corona-treated PET with a roll coater at 100 μm, and a polyamide sheet (thickness 2 mm). ) And left in a constant temperature bath at 23 ° C. and 65% RH for 3 days, and then the 180 ° C. peel strength (N / inch) was measured in accordance with JIS K7311-1995.

[Drop impact resistance evaluation method]
The moisture curable polyurethane hot melt resin compositions obtained in Examples and Comparative Examples were melted at 120 ° C. and dispensed needles (“VALVE MASTER ME- 5000VT ") at a discharge pressure of 0.3 MPa and a speed of 50 mm / sec. On a polyamide sheet (thickness 2 mm: 5 cm x 5 cm) so as to draw a square of 4 cm x 4 cm, and then Acrylic plates were bonded together and left for 3 days at 23 ° C. and 65% RH.
Next, with a DuPont drop impact tester, the presence or absence of peeling of the base material was visually observed under the condition that the impact was applied five times at a load of 300 g and a height of 30 cm through an impact core from an acrylic plate. Judgment was made as follows.
“T”: no peeling occurred.
“F”: Peeling occurred.

[Ejection evaluation method]
Moisture-curable polyurethane hot melt resin compositions obtained in Examples and Comparative Examples were melted to 120 ° C. and dispensed with a 0.6 mmφ inner diameter dispenser needle (“VALVE MASTER ME-5000VT”, Musashi Engineering, preheated to 120 ° C. The discharge performance was determined as follows based on the coating amount (g) when discharged for 10 seconds at a discharge pressure of 0.3 MPa and a speed of 50 mm / second.
“A”; 0.4 g or more and less than 0.5 g “B”; 0.1 g or more and less than 0.4 g “C”; less than 0.1 g

[Reworkability evaluation method]
The obtained laminate was placed in a dryer at 80 ° C. and left for 30 minutes. After standing, the push strength (MPa) was measured in the same manner as in the above [Adhesive evaluation method], and the reworkability was evaluated as follows.
“T”; less than 5 N / inch “F”; 5 N / inch or more

Abbreviations in Tables 1 and 2 will be described.
"PPG2000"; polypropylene glycol, Tmg; -56 ° C, number average molecular weight; 2,000
"Crystalline PEs-2": 1,6-hexanediol and adipic acid reacted, number average molecular weight; 2,000, Tmg; 45 ° C
“Amorphous PEs-1”: a reaction product of 6 mol adduct of bisphenol A alkylene oxide, isophthalic acid and sebacic acid, Tmg; 10 ° C., number average molecular weight; 2,000
"FMDA21";"SilaplaneFMDA21" manufactured by JNC Corporation (in formula (1), R ¹ is an ethyl group, R ² is a propylene group, R ³ is a butyl group, n = 63.7, number average Molecular weight: 5,000
"FMDA26";"SilaplaneFMDA11" manufactured by JNC Corporation (in the formula (1), R ¹ is an ethyl group, R ² is a propylene group, R ³ is a butyl group, n = 198.9, number average) Molecular weight: 15,000

  It has been found that the moisture curable polyurethane hot melt resin composition of the present invention has excellent adhesion to polyamide, ejection properties and drop impact resistance. Moreover, it turned out that adhesiveness falls by heating and it is excellent also in the rework property of a base material.

  On the other hand, Comparative Examples 1 and 2 are embodiments in which the amount of polysiloxane (A-1) having two or more hydroxyl groups deviates from the amount specified in the present invention, but the reworkability is remarkably poor, and the discharge property and resistance The drop impact properties and adhesion to polyamide were not satisfactory.

Claims (6)

Urethane prepolymer having an isocyanate group obtained by reacting a polyol (A) containing a polysiloxane (A-1) having two or more hydroxyl groups in a range of 0.1 to 5% by mass with a polyisocyanate (B). A moisture-curable polyurethane hot-melt resin composition comprising: The moisture-curable polyurethane hot melt resin composition according to claim 1, wherein the polysiloxane (A-1) having two or more hydroxyl groups is represented by the following general formula (1).

(In Formula (1), R ¹ and R ³ each independently represent an alkyl group having 1 to 5 carbon atoms, R ² represents an alkylene group having 1 to 5 carbon atoms, and n represents 1 to 200. Indicates the average value of repeating units.) The moisture-curable polyurethane hot according to claim 1, wherein the polyol (A) further contains a polyether polyol (A-2), a crystalline polyester polyol (A-3) and a polycarbonate polyol (A-4). Melt resin composition. The moisture-curable polyurethane hot melt resin composition according to claim 1, wherein the polyisocyanate (B) is xylylene diisocyanate. An adhesive comprising the moisture-curable polyurethane hot-melt resin composition according to any one of claims 1 to 4. A laminate having an adhesive layer (ii) made of an adhesive according to claim 5 on a base material (i) made of polyamide.